In the related art, when a horn of a vehicle is output to draw a pedestrian's attention, unintentional damage may be caused to the pedestrian due to a louder horn sound.
In order to solve the above-mentioned problem, the driver needs to quickly determine a kind of an object such as a pedestrian, a bicycle, or a vehicle and manually manipulate a button to adjust the horn sound, which may be inconvenient to the driver.
Korean Unexamined Patent Application Publication No. 2013-0061530 discloses a device which controls output of a horn sound of a vehicle. However, the device simply adjusts the volume of the horn of the vehicle in accordance with a position of the vehicle, regardless of an object which is located near the vehicle, so that the problem may not be solved by this device.